Electrode structures



1954 s. A. AANNERUD ELECTRODE STRUCTURES Filed Feb. 13, 1951 IN V ENTOR. 6761690 44. AIIVA/[Rl/D B Y 7,

ATTORNEYS Patented Oct. 12, 1954 EIBEGTRODE STRUCTURES Sigurd ArthurAannerud, ,Thamshavn,,,Norway,- v assignor, by mesne assignments, toPyror L n ited, Pembroke, Bermuda, a corporation,ol.

Bermuda;

Annsafi aremuar 1'ai t1ss rarmimam Claims priority, application NorwayMay 8, 1950 2 Claims. (Cl. 204283) In electrolytic cells it is often ofimportance to make the spacing of anode and cathode as small as possiblein order to reduce the voltage drop and hence the power consumed.Further, in cases where gas is produced at an electrode, it is ofimportance for the economy of the process that the gas is removed fromthe surface of the electrode and replaced by fresh liquid as quickly aspossible.

The present invention relates to electrodes for electrolytic cells ofthe kind in which no deposition is taking place at the electrodeconcerned, but in which gas is developed at the electrode inside adiaphragm separating the anode and cathode compartments, which gas iscollected in a hood above the electrode, and it is an object of theinvention to achieve in this connection the aims above referred to in aparticularly effective and simple manner.

The invention primarily consists in that the electrode is provided onboth sides with low projections distributed over its surface and havinga small top surface on which the diaphragm bears, and the resultinginterstice below the liquid surface cormnunicates both near the top andnear the bottom of the electrode with a liquid reservoir provided in theelectrode under the hood, so that the produced gas rising in theinterstice and entering the reservoir at the top, causes a circulationof the fluid upwards in the interstice and downwards in the reservoir.

Further features of the invention will appear from the followingdescription of a preferred embodiment, which is illustrated in theattached drawings, and which is primarily designed for the anodes of anelectrolytic cell for the electrolytic separation of iron fromFeSOr-solutions, although its use may also be contemplated forelectrodes in other electrolytic processes where similar conditionsprevail.

In the drawings:

Fig. 1 is a view in vertical cross-section of an anode according to theinvention, placed in an electrolytic cell,

Fig. 2 is a fragmentary view of the anode in horizontal cross-section,

Fig. 3 is a fragmentary front view of the anode without diaphragm andpartly in section as indicated by the line IIIIII in Fig. 2.

The anode comprises a pair of parallel plane walls I mutually propped bysuitably spaced cross-walls 2 and connected, at the top, to a positivepole 3 and closed by a rubber hood 4 for collecting oxygen gas which isseparated at the anode by the reaction 2SO4+2H2O 2HzSO4+Oe.

The anode compartment is confined by a diaphragm 5, which is drawntightly onto the anode like a bag and extends upwards into the rubberhood 4, in which it projects above the surface of both the anode and thecathode liquids contained in the electrolytic vessel, in which eachanode is placed upright on a ledge 6 at a distance above the bottom I,so that the vessel forms a communicating cathode compartment for all theindividual cells. The adjacent starting cathodes of sheet iron areindicated on both sides at 8 in Fig. 1.

On their outer faces both walls I are provided, over their entire width,with shallow vertical ribs 9 of triangular cross-section, against whichthe diaphragm bears, partly because it is drawn taut onto the anode bodyI, 2 and partly by so controlling the flow of ferrous sulphate solutionto the cathode compartment and of sulphuric acid solution from the anodecompartment that the catholyte will have a higher static pressure thanthe anolyte and thereby exert a pressure on the diaphragm from outside.The channels l0 formed between the, ribs 9 and covered by the diaphragm,communicate with the interior space of the anode both at the top througha series of upwardly inclined passages l I, and at the bottom where thewalls I are formed with a series of notches I2, each of which is inconnection with one of the channels [0.

Therefore, in operation the hollow space within the anode will form areservoir for anolyte. The oxygen gas is separated off at the anodesurface under the diaphragm 5 and rises through the channels In fromwhich it passes through the passages ll into the interior anode space,in which it rises further so as to be collected above the liquid withinthe hood 4. By this flow the gas will entrain anolyte, so that aconstant flow of anolyte will be maintained, which passes upwardsthrough the channels Ill, then through the passages ll into the interioranode space, downwards through the latter and, through the notches I2,again out into the channels it, whereby the anolyte within thesechannels will constantly be renewed and, at the same time, the upwardliquid flow within the channels It will cause immediate removal of theoxygen gases from the anode surface according as they are formed.

I claim:

1. An electrode structure for electrolytic cells having a hood arrangedat the top of the cell, said electrode structure comprising a pluralityof vertically disposed wall members which are electrically conductive,said wall members being spaced apart and integrally connected forming areservoir open at the top and bottom for receiving electrolyte, aplurality of vertically extending ribs on the outer surfaces of saidwall members, a' diaphragm disposed about said Wall members, a resilienthood embracing the upper portion of said walls and securing saiddiaphragm in place and disposed against said ribs, said walls havingpassageways therethrough in the upper part of each wall for the passageof gas from the outer surface of said walls into the space between thewalls and upward into said hood, said walls having notches along thebottom edges thereof to provide passageways for electrolyte.

2. An electrode structure according to claim 1,

wherein said passageways in the upper part of each wall member arespaced vertically and are upwardly inclined through the walls.

- References Cited in the file of this patent UNITED STATES PATENTSNumber Name Date 1,297,157 Harris Mar. 11, 1919 1,420,037 Harris June20, 1922 FOREIGN PATENTS Number Country Date 196,947 Canada Feb. 3, 1920550,258 Great Britain Dec. 31, 1942 811,238 France Jan. 14, 1937

1. AN ELECTRODE STRUCTURE FOR ELECTROLYTIC CELLS HAVING A HOOD ARRANGEDAT THE TOP OF THE CELL, SAID ELECTRODE STRUCTURE COMPRISING A PLURALITYOF VERTICALLY DISPOSED WALL MEMBERS WHICH ARE ELECTRICALLY CONDUCTIVE,SAID WALL MEMBERS BEING SPACED APART AND INTEGRALLY CONNECTED FORMING ARESERVOIR OPEN AT THE TOP AND BOTTOM FOR RECEIVING ELECTROLYTE, APLURALITY OF VERTICALLY EXTENDING RIBS ON THE OUTER SURFACES OF SAIDWALL MEMBERS, A DIAPHRAGM DISPOSED ABOUT SAID WALL MEM-